Coordinated control for unbalanced operation of stand-alone doubly fed induction generator
Article first published online: 17 DEC 2012
Copyright © 2012 John Wiley & Sons, Ltd.
Volume 17, Issue 2, pages 317–336, February 2014
How to Cite
Li, X., Sun, Y., Su, M. and Wang, H. (2014), Coordinated control for unbalanced operation of stand-alone doubly fed induction generator. Wind Energ., 17: 317–336. doi: 10.1002/we.1577
- Issue published online: 21 JAN 2014
- Article first published online: 17 DEC 2012
- Manuscript Accepted: 3 NOV 2012
- Manuscript Revised: 18 SEP 2012
- Manuscript Received: 4 NOV 2011
- auto-disturbance rejection control (ADRC);
- doubly fed induction generator (DFIG);
- proportional resonant (PR) controller;
- stand-alone wind-power generation;
This paper proposes a coordinated control scheme of a stand-alone doubly fed induction generator (DFIG)-based wind energy conversion system to improve the operation performance under unbalanced load conditions. To provide excellent voltage profile for load, a direct stator flux control scheme based on auto-disturbance rejection control (ADRC) is applied, and less current sensors are required. Due to the virtues of ADRC, the controller has good disturbance rejection capability and is robust to parameter variation. In the case of unbalanced loads, the electromagnetic torque pulsations at double synchronous frequency will exist. To eliminate the undesired effect, the stator-side converter (SSC) is used to provide the negative sequence current components for the unbalanced load. Usually, proportional integral controllers in a synchronous reference frame are used to control SSC. To simplify the algorithm, an improved proportional resonant (PR) control is proposed and used in the current loop without involving positive and negative sequence decomposition. The improved PR provides more degree of freedom which could be used to improve the performance. The effectiveness of the proposed control scheme has been validated by the simulation and experimental results. Copyright © 2012 John Wiley & Sons, Ltd.